Yahoo! News - Study: Marijuana Buzz Linked to 'Runner's High'
ATLANTA (Reuters) - The same family of chemicals that produces a buzz in marijuana smokers may be responsible for "runner's high," the euphoric feeling that some people get when they exercise, U.S. researchers say.

High levels of anandamide were found in young men who ran or cycled at a moderate rate for about an hour, according to a study made public this week by the Georgia Institute of Technology and the University of California, Irvine.

Anandamide is a cannabinoid, or lipid molecule, that is naturally produced in the body. It is known to produce sensations that are similar to those of THC, the psychoactive property in marijuana.

Well, THAT is interesting. I think I need an exercise bike now...